1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef NETD_SERVER_NETWORK_CONTROLLER_H
18#define NETD_SERVER_NETWORK_CONTROLLER_H
19
20#include "NetdConstants.h"
21#include "Permission.h"
22
23#include "utils/RWLock.h"
24
25#include <list>
26#include <map>
27#include <set>
28#include <sys/types.h>
29#include <vector>
30
31class DumpWriter;
32class Network;
33class UidRanges;
34class VirtualNetwork;
35
36/*
37 * Keeps track of default, per-pid, and per-uid-range network selection, as
38 * well as the mark associated with each network. Networks are identified
39 * by netid. In all set* commands netid == 0 means "unspecified" and is
40 * equivalent to clearing the mapping.
41 */
42class NetworkController {
43public:
44    static const unsigned MIN_OEM_ID;
45    static const unsigned MAX_OEM_ID;
46    static const unsigned LOCAL_NET_ID;
47    static const unsigned DUMMY_NET_ID;
48
49    NetworkController();
50
51    unsigned getDefaultNetwork() const;
52    int setDefaultNetwork(unsigned netId) WARN_UNUSED_RESULT;
53
54    // Sets |*netId| to an appropriate NetId to use for DNS for the given user. Call with |*netId|
55    // set to a non-NETID_UNSET value if the user already has indicated a preference. Returns the
56    // fwmark value to set on the socket when performing the DNS request.
57    uint32_t getNetworkForDns(unsigned* netId, uid_t uid) const;
58    unsigned getNetworkForUser(uid_t uid) const;
59    unsigned getNetworkForConnect(uid_t uid) const;
60    void getNetworkContext(unsigned netId, uid_t uid, struct android_net_context* netcontext) const;
61    unsigned getNetworkForInterface(const char* interface) const;
62    bool isVirtualNetwork(unsigned netId) const;
63
64    int createPhysicalNetwork(unsigned netId, Permission permission) WARN_UNUSED_RESULT;
65    int createVirtualNetwork(unsigned netId, bool hasDns, bool secure) WARN_UNUSED_RESULT;
66    int destroyNetwork(unsigned netId) WARN_UNUSED_RESULT;
67
68    int addInterfaceToNetwork(unsigned netId, const char* interface) WARN_UNUSED_RESULT;
69    int removeInterfaceFromNetwork(unsigned netId, const char* interface) WARN_UNUSED_RESULT;
70
71    Permission getPermissionForUser(uid_t uid) const;
72    void setPermissionForUsers(Permission permission, const std::vector<uid_t>& uids);
73    int checkUserNetworkAccess(uid_t uid, unsigned netId) const;
74    int setPermissionForNetworks(Permission permission,
75                                 const std::vector<unsigned>& netIds) WARN_UNUSED_RESULT;
76
77    int addUsersToNetwork(unsigned netId, const UidRanges& uidRanges) WARN_UNUSED_RESULT;
78    int removeUsersFromNetwork(unsigned netId, const UidRanges& uidRanges) WARN_UNUSED_RESULT;
79
80    // |nexthop| can be NULL (to indicate a directly-connected route), "unreachable" (to indicate a
81    // route that's blocked), "throw" (to indicate the lack of a match), or a regular IP address.
82    //
83    // Routes are added to tables determined by the interface, so only |interface| is actually used.
84    // |netId| is given only to sanity check that the interface has the correct netId.
85    int addRoute(unsigned netId, const char* interface, const char* destination,
86                 const char* nexthop, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
87    int removeRoute(unsigned netId, const char* interface, const char* destination,
88                    const char* nexthop, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
89
90    bool canProtect(uid_t uid) const;
91    void allowProtect(const std::vector<uid_t>& uids);
92    void denyProtect(const std::vector<uid_t>& uids);
93
94    void dump(DumpWriter& dw);
95
96private:
97    bool isValidNetwork(unsigned netId) const;
98    Network* getNetworkLocked(unsigned netId) const;
99    VirtualNetwork* getVirtualNetworkForUserLocked(uid_t uid) const;
100    Permission getPermissionForUserLocked(uid_t uid) const;
101    int checkUserNetworkAccessLocked(uid_t uid, unsigned netId) const;
102
103    int modifyRoute(unsigned netId, const char* interface, const char* destination,
104                    const char* nexthop, bool add, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
105    int modifyFallthroughLocked(unsigned vpnNetId, bool add) WARN_UNUSED_RESULT;
106
107    class DelegateImpl;
108    DelegateImpl* const mDelegateImpl;
109
110    // mRWLock guards all accesses to mDefaultNetId, mNetworks, mUsers and mProtectableUsers.
111    mutable android::RWLock mRWLock;
112    unsigned mDefaultNetId;
113    std::map<unsigned, Network*> mNetworks;  // Map keys are NetIds.
114    std::map<uid_t, Permission> mUsers;
115    std::set<uid_t> mProtectableUsers;
116};
117
118#endif  // NETD_SERVER_NETWORK_CONTROLLER_H
119